German patent application DE 102 33 549 describes a scanning microscope with a light source which, in order to illuminate a sample, emits an illuminating light beam which travels along an illuminating beam path and can be guided over or through the sample by a beam deflection device. A detector receives the detection light which emanates from the sample and travels along a detection light beam path. A further light source produces a manipulating light beam which travels along a manipulating beam path. The manipulation light beam can also be guided over or through the sample by the beam deflection device.
German laid-open patent application DE 199 54 933 describes an arrangement for coupling at least one beam of optical tweezers for capturing particles and/or a processing beam into a microscope beam path, preferably in a laser scanning microscope. Means are provided to freely change the location of the beam focus of the optical tweezers and/or the processing beam with respect to the change of the focal position of the microscope.
U.S. Pat. No. 6,094,300 describes a laser scanning microscope which has two scanning devices. In this case, the illuminating beam is guided by one scanning device, while a further illuminating beam or manipulating light beam is guided, for example, by the other scanning device. The light beams coming from the two scanning devices are brought together in such a manner that they are incident in unison on a point of the sample. However, this arrangement is difficult to manipulate.
The aforementioned devices have the disadvantage that if areas of a sample which are larger than the focus of the illuminating light beam are to be manipulated, these areas have to be scanned by the manipulating beam. This is awkward and time consuming and makes it impossible to investigate fast processes.